In an X-ray analysis device, generally, fluorescent X-rays (characteristic X-rays) generated by irradiating a sample with excitation X-rays are detected and the energy (wavelength) and intensity (dose) of the fluorescent X-rays are determined. Since the fluorescent X-rays (characteristic X-rays) emitted from a sample have element-specific energy (wavelength), by determining the energy (wavelength) of the fluorescent X-rays, it is possible to identify the elements contained in the sample, and based on the intensity (dose) thereof, it is possible to find out the concentration of the elements.
X-ray analysis devices are classified according to the manner of analysis of the energy (wavelength) of fluorescent X-rays as energy dispersive or wavelength dispersive. In an energy dispersive X-ray analysis device, fluorescent X-rays emitted from a sample are directly detected by an X-ray detector comprising a semiconductor detector or the like, and using the fact that the wave height of the detection output is correlated with the energy of the X-rays, the output signal of the X-ray detector is sorted according to wave height, and the dose for each wave height, and thus for each energy, is determined. On the other hand, in a wavelength dispersive X-ray analysis device, fluorescent X-rays emitted from the sample are separated by wavelength using an analyzing crystal or the like, and the X-ray dose at each wavelength is detected.
In X-ray analysis devices as described above, a technique called mapping analysis is known. Mapping analysis is an analytical method in which the irradiation location of X-rays on a sample is successively changed, fluorescent X-rays are detected at each X-ray irradiation location, and analysis is performed as described above to determine the concentration distribution of elements at each location of the sample.
In order to perform this sort of mapping analysis, usually, a configuration is employed whereby the sample is secured to a displacement mechanism such as an XY stage, and that displacement mechanism is driven to move the sample in relation to a fixed X-ray irradiation location of excitation X-rays from the X-ray tube.
Taking an energy dispersive X-ray analysis device as an example, the essential parts of the configuration of a conventional device capable of mapping analysis are shown in FIG. 4. A sample W is positioned and secured on an XY stage 101, and X-rays from an X-ray tube 102 are irradiated via a collimator 103 as excitation X-rays 108 onto that sample W. Fluorescent X-rays 109 emitted from the sample W as a result of this irradiation are inputted into an X-ray detector 106 and are detected. The output of the X-ray detector 106 is acquired by a measurement circuit 107 such as a multichannel analyzer and is amplified, after which wave height analysis and counting of signals at each wave height are performed.
The XY stage 101 is driven under the control of a stage controller 110, and moves and positions the sample W so that the irradiation location of excitation X-rays 108 on the sample W successively changes within a preset range (for example, see Patent Literature 1).
In this way, since the excitation X-ray irradiation location is fixed and the sample W is moved, an XY stage is necessary, and in the case of a configuration capable of handling relatively large samples, the device becomes bulky, and to resolve this problem, the technique of moving the collimator so as to change the irradiation location of excitation X-rays on the sample has been proposed (for example, see Patent Literature 2).
Namely, according to the technique disclosed in Patent Literature 2, the X-ray tube and sample are fixed and a collimator having a through-hole, disposed between them, is moved, thereby changing the X-ray irradiation location on the sample.